The instant invention relates to covers for gondola cars which are open top railroad cars frequently used to transport bulk materials. More particularly, the instant invention relates to removable covers for gondola cars.
Nuclear and hazardous chemical wastes are usually shipped by truck to dump sites in containers approved by the Department of Transportation. However, the volume of such wastes has become so large that railroads are now being employed for its disposal.
During the past several years, the identification of hazardous nuclear and chemical waste sites has resulted in enormous quantities of dangerous waste which is most economically disposed of by transporting the waste from contaminated sites to isolated dumping sites. Of particular concern is soil contaminated by uranium mill tailings which is a low level radioactive material having a very large volume. The contaminated soil must be retained in gondola cars until the soil arrives at its dump. Since air currents blow over the gondolas while transporting the soil, there is the danger of the area adjacent the railroad tracks becoming contaminated by airborne radioactive particles. Since a large percentage of the particles tend to settle, repeated passage of trains transporting radioactive soil will cause over time a dangerous accumulation of radioactive material adjacent the tracks. Accordingly, it is necessary to cover gondola cars.
In accordance with present practice, gondolas are covered with a disposable plastic cover which is removed when the gondola arrives at the dump site and disposed of with the hazardous contents of the gondola. Both the inside and outside of the gondola must then be decontaminated prior to being released for a return trip or further service. The cost of disposable covers and cost of decontaminating gondolas is considerable. Accordingly, there is a need for another approach for covering gondola cars.
As is evident from the prior art, there are a number of covers which may be attached to or retrofitted to gondola cars such as the covers exemplified in U.S. Pat. Nos. 2,985,118; 3,106,900; 3,631,816; and 2,674,280. These covers are, however, quite expensive, heavy and difficult to retrofit. Since operations such as removing soil from sites contaminated by uranium mill tailings require enormous numbers of gondola cars, the expense of utilizing only covered cars or retrofitting cars available from existing rolling stock can be prohibitive. There are, of course, lightweight fabric covers as exemplified by U.S. Pat. Nos. 4,823,708 and 3,044,653. However, these covers, according to regulations and for safety purposes, must be disposed of at the site in the same manner as currently used plastic covers.
In view of these considerations and other considerations, there is a need for a gondola cover which is relatively inexpensive, lightweight, reusable and readily retrofittable to existing rolling stock. The cover is of special interest for shipping low level radioactive waste such as soil contaminated by uranium mill tailings.